Osseointegration of preformed polymethylmethacrylate craniofacial prostheses coated with bone marrow-impregnated poly (DL-lactic-co-glycolic acid) foam

Osseointegration of bone marrow-PLGA-coated, preformed polymethylmethaclyla te cranioplasties offers the possibility of reducing: operative time, perii mplant seroma and infection, metallic fixation, and periprosthetic resorpti on following surgical skull remodeling. These alloplastic materials are FDA -approved but previously have not been used together to promote cranioplast y incorporation. The objective of this study was to determine whether the use of PLGA foam c oating improves host osseointegration of preformed, textured, polymethylmet hacrylate prosthetic cranioplasties. A critical-sized cranial defect was created in two groups of 10 and one gro up of three rabbits. The defect was filled with either a textured, preforme d polymethylmethacrylate disc or a textured, preformed polymethylmethacryla te disc coated with poly (DL-lactic-co-glycolic acid). Both implants were i mmersed in autologous bone marrow for 20 minutes before implantation. Half of each group of 10 were killed at 3 weeks, and the remainder at 6 weeks. A third group of three rabbits with excised periosteum was evaluated at 6 we eks. Histologic analysis of the discs determined relative amounts of cancel lous bone formation adjacent to the prostheses. Woven trabecular bone was present at each host bone to implant perimeter in terface at 3 weeks, with fine fibrous capsular formation around the implant s. Thicker, lamellar trabeculae were present at 6 weeks with an increased f ibrous layer surrounding both types of implants. Bone formed on the superfi cial and deep implant surfaces in a noncontiguous fashion. Two of five meas ures showed that total bone formation was significantly greater in the PLGA -coated implants. Polymethylmethacrylate discs coated with bone marrow-impregnated PLGA foam demonstrate increased bone formation at 3 and 6 weeks as compared with nonc oated preformed polymethylmethacrylate discs. Only implants with preserved periosteum showed bone formation away from the host-implant interface (cent rally) on the superficial surface at 6 weeks.